What I would choose (and I've advocated for before) isn't represented in the above.
* Eschew the GM as Jedi and aspiring GM as padawan relationship. I don't feel like this has been good for our hobby at all. Don't let someone's idea of what you should be doing infect your curiosity and creativity and boldness. Its just as likely or more to curtail you or frighten you as it is to aid you.
* Read the book or book that you're trying to run. Imagine play. Work hard to conceive "what is this game trying to do" and "how does this game do that thing?"
* Practice discrete conflicts where you aren't burdened with maintaining a through line of narrative continuity so you can focus on making this particular thing awesome and running it correctly. Focus on the type of stuff that is fundamental to play while you aren't burdened with the fear and stress of running a game. Practice combats. Practice social conflicts. Practice expeditions/journeys and all that goes with that (presenting multiple compelling routes foregrounding conflict and telegraphing consequences of alternative routes, climbing obstacles, hazard-spanning obstacles, supernatural obstacles, denizens and locales etc). Practice fleeing/chases/driving off enemies. Practice supernatural conflicts. Practice the constituent parts for that are seminal/important for this game to work.
* Practice again. Think small and focused and work on your fundamentals. Think of how situation-framing and scenario-design create decision-points that are provocative and compelling. Think how twists and turns in the fiction and gamestate post-action resolution make for a better or worse play experience with respect to "what is this game trying to do."
* Now put it all together and boldly run a game.
* Be honest with your players and ask the same of them. Make sure your relationship is open and understanding.
* Be humble about your play. Make corrections. Do it again.
